Cogent from various west coast USA locations seems to have trouble getting to some Comcast ipv6 addresses: Cogent LG Los Angeles to www.comcast6.net traceroute to 2001:558:fe16:7:69:252:216:215 (2001:558:fe16:7:69:252:216:215), 30 hops max, 80 byte packets 1 2001:550:1:317::1 (2001:550:1:317::1) 70.184 ms 70.181 ms 2 * * 3 * * 4 2001:550:4::51 (2001:550:4::51) 15.013 ms 14.981 ms 5 * * 6 * * [ ... ] Cogent LG San Francisco ipv6 trace to www.comcast6.net traceroute to 2001:558:fe16:7:69:252:216:215 (2001:558:fe16:7:69:252:216:215), 30 hops max, 80 byte packets 1 2001:550:1:31f::1 (2001:550:1:31f::1) 0.367 ms 0.369 ms 2 * * 3 * * 4 * * [ ... ] Cogent LG San Jose ipv6 ping to www.comcast6.net PING 2001:558:fe16:7:69:252:216:215(2001:558:fe16:7:69:252:216:215) 56 data bytes --- 2001:558:fe16:7:69:252:216:215 ping statistics --- 5 packets transmitted, 0 received, 100% packet loss, time 13999ms Cogent LG San Jose ipv6 ping to speedtest.comcast.net (Los Angeles does same thing, but Kansas City works): PING 2001:558:fe2a:3:69:241:64:6(2001:558:fe2a:3:69:241:64:6) 56 data bytes --- 2001:558:fe2a:3:69:241:64:6 ping statistics --- 5 packets transmitted, 0 received, 100% packet loss, time 14000ms from Los Angeles same thing, but from Cogent's LG Kansas City it works: PING 2001:558:fe2a:3:69:241:64:6(2001:558:fe2a:3:69:241:64:6) 56 data bytes 64 bytes from 2001:558:fe2a:3:69:241:64:6: icmp_seq=1 ttl=55 time=35.6 ms 64 bytes from 2001:558:fe2a:3:69:241:64:6: icmp_seq=2 ttl=55 time=35.7 ms 64 bytes from 2001:558:fe2a:3:69:241:64:6: icmp_seq=3 ttl=55 time=35.6 ms 64 bytes from 2001:558:fe2a:3:69:241:64:6: icmp_seq=4 ttl=55 time=35.6 ms 64 bytes from 2001:558:fe2a:3:69:241:64:6: icmp_seq=5 ttl=55 time=35.6 ms --- 2001:558:fe2a:3:69:241:64:6 ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 4043ms rtt min/avg/max/mdev = 35.620/35.676/35.734/0.241 ms This is similar to issues I see with a Cogent IPv6/BGP-enabled transit connection in Los Angeles to a random Comcast customer address (that is otherwise up and reachable from HE.net, NTT, etc): (from router with ipv6 BGP Cogent transit connection): traceroute6 to 2601:7:1300:3d2::1 (2601:7:1300:3d2::1) from 2001:550:2:18::5:2, 64 hops max, 12 byte packets 1 2001:550:2:18::5:1 (2001:550:2:18::5:1) 1.903 ms 1.120 ms 10.771 ms 2 * * * 3 * 2001:550::57 (2001:550::57) 15.654 ms * MPLS Label=19852 CoS=2 TTL=255 S=0 MPLS Label=19207 CoS=2 TTL=255 S=1 4 * * * I have Cogent ticket #HD0000005706297 on that but I'm being ignored. I see the similar things from Cogent IP6 transit out of San Jose. Anyone at Cogent able to look at this? I basically blackhole big chunks of Comcast ipv6 on my network when I enable ipv6 to Cogent. -Will